Hitherto, vessels for aerosol of hair spray, insecticide, and the like are mainly made of metal such as tin, aluminum, or the like.
In recent years, the vessels for aerosol made of plastics have been put into practical use. Polyester, high-nitrile resin, or the like is used for such a container.
Particularly, the high-nitrile resin is suitable because it is excellent in gas barrier property and chemical resistance, and its practical use is progressing.
However, since the high-nitrile resin has a hygroscopicity, if a content contains the water, the vessel itself absorbs the moisture and a softening temperature decreases, so that there is a problem such that the vessel is deformed due to an increase in inner pressure at high temperatures of 50.degree. to 70 .degree. C.
On the other hand, in the case of vessels made of a resin, not only the cylindrical vessels such as a conventional vessel made of metal but also heteromorphic vessels having a cross section of an ellipse, a rectangle, or the like can be obtained. However, at high temperatures of 50.degree. to 70.degree. C., there is a problem such that what is called environmental stress cracks occur depending on the vessel shape, that is, the inner pressure increases at such high temperatures, stresses are concentrated to a part of the container, chemicals of the content touch this portion, and cracks are caused.